---
id: po.wb.dca.decline-functions
title: Decline Curve Analysis — Arps with EUR
category: DCA
tags:
  - decline-curve
  - arps
  - eur
  - economic-limit
  - production-forecast
  - b-exponent
  - sensitivity
---

# Decline Curve Analysis — Arps with EUR

## Purpose

Complete Arps decline analysis: forecast rate and cumulative production over 20 years,
calculate EUR at economic limit, and compare b-exponent sensitivity (b=0, 0.5, 1.0).
Named input cells for qi, Di, b, and economic limit rate.

## Plan

- [x] Inputs sheet with named cells
- [x] Forecast sheet: 21 time steps out to 240 months, rate + Np + decline %
- [x] EUR and time-to-economic-limit calculations
- [x] b-exponent sensitivity: exponential vs hyperbolic vs harmonic
- [x] 4 charts: rate, cumulative, sensitivity
- [ ] Add modified hyperbolic (ModHyp) comparison